Optimal Hedging Ratios for Wheat and Barley at the LIFFE: A GARCH Approach

Abstract

Over 100,000 futures contracts for cereals are traded annually on the London International Financial Futures Exchange. The proportion of the spot position held as futures contracts ‐ the hedging ratio ‐ is critical to traders and traditional estimates, using OLS, are constant over time. In this paper, we estimate time‐varying hedging ratios for wheat and barley contracts using a multivariate generalised autoregressive conditional heteroscedasticity (GARCH) model. Results indicate that GARCH hedging ratios do change through time. Moreover, risk using the GARCH hedge is reduced significantly by around 4 per cent for wheat and 2 per cent for barley relative to the no hedge position, and significantly by around 0.2 per cent relative to the constant hedge. The optimal, expected utility‐maximising, and the risk‐minimising hedging ratios are equivalent.